Md. Code, Tax - Property § 8–230

(a) In this section, “improvements” means improvements made before January 1, 1977, to real property:

(1) occupied by the owner; and

(2) used as the principal place of residence of the owner.

(b) Except for flooding solely caused by tidal water, improvements shall be assessed on the basis of the reduced value of the improvements if the improvements had been damaged by and were subject to a substantial threat of recurring damage by:

(1) flooding;

(2) shifting land masses; or

(3) unstable soils or soil fault conditions.